In the context of the invention a “zero knowledge” connection is a connection for purposes of data communication between an electronic unit and computer, for example, a technician's notebook, in which security-relevant data, such as RSA keys, or crypto-keys, which correspond to the current security standards, and passwords, do not have to be entered manually and are not known to the user of the computer.
From the prior art, for purposes of maintenance or for purposes of configuration of an electronic unit, for example, a vending machine or a conditional access device, it is of known art to make a direct connection between the technician's computer and the unit that is to be configured. A direct connection is required, since the firewall in the network, in which the unit to be configured is connected, must be bypassed in order to be able to access the electronic unit.
As a general rule the connection between the computer and the electronic unit that is to be configured takes place by means of the SSH-protocol (secure shell protocol), which enables a manual configuration and the alteration of parameters. This in turn means that the technician requires items of information regarding the unit and the installed operating system, together with the relevant parameters. Moreover, a knowledge is required of the passwords and, if necessary, of the RSA keys, or crypto-keys, which correspond to the current security standards, which are used in order to make a connection by means of the SSH-protocol. Since as a general rule these security-relevant items of information are stored on the technician's computer, this represents a security risk.